Heat pump



M. M. SMITH April 11, 1950 HEAT PUMP 2 Sheets-Sheet 1 Filed Oct. 25,1945 Ap 1950 M. M. SMITH 2,503,456

HEAT PUMP Filed Oct. 25, 1945 2 Sheets-$heet 2 AIR Patented Apr. 11,1950 HEAT PUMP Marvin M. Smith, Muncle, Ind., assignor to 1:10., Muncie,Ind., a cor- Muncie Gear Works,

poratlon of Indiana Application October 25, 1945, Serial N0. 624,351

4 Claims.

This invention relates to devices making use of the refrigeration cyclefor pumping heat from one place to another and has particular referenceto apparatus in which subterranean water is used as a source of heatwhich, combined with the heat of the mechanical energy expended in theoperation of the apparatus, is utilized for the purpose of heatingbuildings. A suitable app ratus for this purpose is described inconsiderable detail in my copending joint application with Clesent 0.Fields and Emory N. Kemler, Serial No. 574,478 filed January 25, 1945,which issued as Patent No. 2,401,890, July 11, 1946, and the presentinvention is mainly directed to improvements having particular referenceto specific construction for utilizing the natural heat of asubterranean source in connection with apparatus of the general class ofheat pumps represented by said patent.

The main objects of this invention are to provide an improved form ofdeep well apparatus for use in connection with devices operating in therefrigeration cycle; to provide improved means for utilizing the deepwell either directly or indirectly as one of the heat transfer elementsof the refrigeration cycle; and to provide improved means for insuringeflective transfer of heat to or from the water of the deep well inenvironments where the water of the well may be normally static.

A specific embodiment of this invention is shown in the accompanyingdrawings in which:

Figure 1 illustrates diagrammatically a heat pump apparatus having deepwell connections arranged in accordance with this invention. Someapparatus features not essential to the operation of this invention areomitted to simplify the disclosure.

Fig. 2 is a diagrammatic view of a modified arrangement in which thedeep well is used directly as the evaporator of the refrigeration cycle.

Fig. 3 is a diagram of a modified form of the same in which the deepwell serves directly as the condenser element of the refrigerationcycle.

In the form shown in Figure 1, the principal elements of therefrigeration cycle of the heat pump are represented by a compressor l,a condenser 2, an expansion valve 3, and an evaporator 4 connected in aclosed circuit for circulation of a refrigerant by means of pipes 5, 6,I and 8.

The heat-exchange devices which serve as condenser and evaporator inthis refrigeration cycle comprise refrigerant coils l0 and 9respectively,

and a second set of coils H and I2 whereby liquid heat-convcying mediumis circulated in heat-transferring relation to the coils 9 and ill. Thecoils H and I2 are separately connected, in closed circuit to anelongated U-tube l3 extending into a deep well l4.

The inlet ends of the coils H and II are connected by pipes l5 and I5respectively through a three-way valve I! to one leg I! of the U-tube IIand their outlet ends are connected by pipes II and 20 respectively tothe other leg 2| of the U-tube l3. The legs of the U-tube are equippedwith circulating pumps 22 and 23 respectively which may have a commondrive shaft 24 driven by a motor 25 or belted to the motor of thecompressor as will be understood.

The circulating pumps 22 and 23 work in opposite directions forcontinuous circulation of the liquid contents of the U-tube and itsconnected piping. The medium contained in this piping may be anysuitable liquid that is anti-freezing in the range of temperatures thatmight exist at any time at any point along its length.

The heat-transferring coils of the evaporator and condenser areseparately enclosed in tubular housings 26 and 21 which may bealternately closed by a pair of bailles 28 which are shiftable so as tocause the air that is to be conditioned by the apparatus to flow eitherthrough the evaporator housing 26 when the air is to be cooled by theapparatus or through the condenser housing 2'! when the air is to beheated.

Similarly, the three-way valve I! may be shifted so as to supplycirculating medium either to the coil ll of the evaporator or to thecoil l! of the condenser so as to be effective only in that respectiveheat-transfer device which is cut 03 from the air flow.

The deep well apparatus of the present invention consists of a bore l4extending down into the earth to a sufllcient depth to insure that itreaches well below the normal level of the subterranean waterrepresented by the broken line 30. The bore I4 is provided with asuitable casing 3| in its upper part. The bore may be comparativelysmall in diameter and may extend deep into the earth. It will, ofcourse, be understood that dimensions of the well and piping are subjectto variations according to the capacity of the apparatus.

A suitable form of U-tube for use in such a well might consist of a pairof pipes l8 and 2|. assembled in parallel relation to each other, as

shown in the drawings, and connected at their lower ends by means of aU-fitting 32. F'lns 3M may be provided for increasing the heattransferring surface of the tube l3.

In the illustrative modifications shown in Figs. 2 and 3, the deep wellU-tube is employed directly as a part of the piping circuit throughwhich the refrigerant is circulated. In Fig. 2 the U-tube serves as theevaporator and in Fig. 3 it serves as the condenser of the refrigerationcycle. In each of these cases, the compressor l serves as a circulatingpump and it is unnecessary to equip the U-tube with the circulating pumpof Figure 1.

when the heat pump is used for cooling air, the air is directed over thecoils of the evaporator as indicated by the arrow 36, in Fig. 1; andwhen the heat pump is used for heating air, the flow of air is directedover the coils of the condenser as indicated by the arrow 31 in Fig. 1.It is thought to be unnecessary, in view of the present state of theart, to include in this disclosure the surrounding casing andarrangement of air ducts, blower and other devices for controlling suchair flow. A suitable structure for this purpose is shown in thebefore-mentioned copending application, Patent No. 2,401,890.

It is important that there be no substantial transfer of heat from oneof the legs of the U-tube to the other in the upper part of the U-tubeand that the water in the well be kept in motion, especially if the wellis of comparatively small diameter. To this end the down-flow leg 2| ofthe U-tube l3 in Fig. l is enclosed in a tubular casing 33 which extendsfrom the top of the well throughout the length of the leg 2|, beingspaced from the walls thereof to form a duct, which is preferablyextended below the bottom of the U-tube if the depth of the wellpermits. A water-intake pipe 34 extends into the upper part of the wellfrom a point substantially below the normal water level 30 to the top ofthe well where it is joined to the casing 33 through a water pump 35,whereby water is taken from the upper part of the well and is forced toflow along the leg 2| of the U-tube and to the lower part of the well.The water of the well thus has a heat-transfer stimulating action byreason of its wiping effect along the surfaces of the U-tube and alsoover the walls of the well. This last-named circulating pump 35 may alsobe driven by the same motor 25 that operates the pumps 22 and 23.

In the operation of the system shown in Fig. 1, with the systemfunctioning for heating purposes, the air to be heated is directedacross the condenser portion 2, as indicated by the arrow 31, the baille"being in position to block off the evaporator portion 4. The three-wayvalve i1 is set to direct the heat transfer fluid, in the closedcirculating system of the U-tube I3, through the heat exchanger coil IIand then back to the U tube and the pumps 22 and 23 are operated toforce the fluid circulation.

With this adjustment heat from the well water is conveyed, by the closedliquid circulating system, directly to the evaporator coils 9 of theheat pump system and absorbed by the refrigerant in the heat pumpsystem. Such heat is then delivered through the compressor to thecondenser coil l where it is transferred by convection to the airpassing through the condenser portion 2.

The circulation in the closed heat transferring fluid system isupwardfrom the well through the U -tube leg l8, through the pump 22 anddownward into the well through the U-tube leg 2| by way of the pump 23.Thus the cooled fluid from the coil II is returned to the well where itis reheated by absorption from the well water surrounding the U-tube.

In order to prevent cooling of the well water in the upper portion ofthe well, where the highest relative well water temperature is desired,the downward leg 2| is insulated. throughout its length by means of thejacket tube 33. Also the well water is circulated through the jackettube in order to immediately begin the process of reheating thecirculating heat conducting fluid. Such well water is taken from theupper portion of the well and is discharged adJacent the bottom conduitcomprising means arranged of the well in order to provide a maximum ofheat exchange contact with the well sides as the well water is thusprogressively moved or circulated within the well bore. I

When the heat pump system is operated for cooling purposes, the ballle28 is shifted to close off the condenser portion 2 and the air to becooled is directed through the evaporator portion 4. Under theseconditions the valve i1 is turned to direct the flow of heat conductingfluid from the pump 22 to the coil I2 and the heat conducting fluid thenserves the function of removing heat from the heat pump system anddumping such heat into the well where it is dissipated to the ground.

Under these circumstances the well serves as a cooling means. However,the flow of fluid through the U-tube portion of the closed circulatingsystem is the same as when operating on the heating cycle. In this casethe jacket tube 33 serves to prevent heating of the well water at theupper portion of the well and the well water circulating through thejacket removes most of the heat from the heat conducting fluid in theleg 2| and dumps the heated water at the bottom of the well bore wherebymaximum heat transfer contact between the walls of the well and thewater moving in the well is obtained.

Although one specific embodiment of this invention is shown inconsiderable detail and some modifications are also herein shown anddescribed, it will be understood that numerous details of theseconstructions may be altered or omitted without departing from thespirit of this invention as defined by the following claims.

I claim:

1. In a heat pump, a refrigeration cycle apparatus comprising acompressor and a pair of refrigerant heat exchange members connected tofunction as condenser and evaporator respecitvely, a well bore extendinginto the earth, and a closed circuit heat-conveying fluid circulation inheat transfer relation to one of said refrigerant heat exchange membersand including a U-tube extending into said well bore in series with saidconduit, said U-tube having heat transfer relation to the contents ofthe well bore.

2. In a heat pump system, a refrigerant circulating system, a well boreextending below the prevailing subterranean water level and incommunication with such water, a U-tube extending into said well bore toa point below said water level, a closed circulatory piping systemincluding a portion having heat exchange relation to said refrigerantcirculating system and including said u-tube and a pump, a heatconducting liquid in said U-tube and circulatory piping system, a casingenclosing one leg only of said U- tube, and means including a secondpump for causing the water in said well to circulate through saidcasing.

3, In a heat pump system, a well bore extending below the prevailingsubterranean water level,

'a U-tube extending into said well bore to a point below said waterlevel, a closed circulatory piping system arranged in heat exchangerelation with the heat pump and including a pump in said system abovesaid U-tube, a heat conducting liquid in said U-tube and circulatorypiping system, and mechanical means for causing the water in said wellto circulate about said U-tube, said mechanical means comprising acasing enclosing and forming a water passage extending along 15 one legonly of said U-tube, and means including accuse I a pump for forcing aflow of water from said well and through said casing parallel with theflow of liquid in said one leg.

4. In a heat pump system, a well bore extending below the prevailingsubterranean water level, a U-tube extending into said well bore to apoint below said water level in heat transfer relation thereto, a closedcirculatory pipingsystem arranged in heat exchange relation with theheat pump and including a pump in said system above said U-tube, a heatconducting liquid in said U- tube andcirculatory piping system,mechanical means for causing the water in said well to circulate aboutsaid U-tube, said mechanical means comprising a casing enclosing andforming a water passage extending along one leg only of said U-tube fromthe upper part of said well to a point substantially below the bottom ofsaid U-tube, and a pump for forcing a flow of water from said well andthroush said casins.

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REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

